The present invention relates to a power source element, such as a battery or an electric double layer capacitor, having connecting terminals or terminal leads bonded to positive and negative electrode cases thereof.
As the development of electronic appliances advances, batteries or electric double layer capacitors with terminal leads welded to the positive and negative electrodes of the cases thereof are being broadly used in electronic circuit boards with the above terminal leads soldered thereon. Above all, button type lithium batteries, lithium ion secondary batteries and electric double layer capacitors have been widely utilized in applications such as memory backup. The terminal leads have had a thickness of from 0.1 mm to 0.3 mm to provide strength in order to satisfy the requirement for high reliability of battery function retention.
In recent years, as the concerns over environmental problem increase there have been increased demands on the designing stage to facilitate disassembling upon scrapping and reduce the materials to be separated. In the case where a battery or electric double layer capacitor is welded with terminal leads and thereafter soldered onto a board for usage, it is not easy to remove and separate the battery or electric double layer capacitor upon scrapping.
It is therefore an object of the present invention to provide a power source element, such as a battery or an electric double layer capacitor, with terminal leads which retains high reliability while reducing the burden of environmental considerations when being scrapped.
In accordance with the present invention, there is provided a power source element, such as a battery or an electric double layer capacitor, having terminal leads bonded to the positive electrode case and the negative electrode case thereof, and in which a mechanism (such as a cutting or breakable portion formed along a weakened line) is provided in each of the terminal leads to facilitate cutting, e.g., a thickness-reduced portion, a cut-out notch, perforation-like holes or the like.